THE financial crisis will likely leave behind a much smaller Wall Street, relative to both the nation’s and the city’s economy. But it may well leave New York’s financial industry in better long-term shape than London’s, if Mayor Bloomberg takes the right steps.

In the last six weeks, unheralded successful government regulations have ably served investors who kept their money in America – a modest achievement that gives us a modest foundation to rebuild on.

Both New York and London are acutely dependent on finance. Over there, it’s about 22 percent of gross city product; here, it’s 14 percent. Over there, financial-industry jobs are about 11 percent of total city employment; here, they’re 13 percent. And both cities are in for (more) massive job losses as the financial-services model for the past 25 years – big companies taking on lots of risk with easy-money borrowing – has disintegrated.

Yet New York could have one important advantage.

In the future, Wall Street’s business likely will turn away from borrowing, structuring, buying and selling for short-term returns and toward the boring old business of managing assets – stocks, bonds, commodities, etc. – for people and institutions.

And in the current market rout, America so far seems to have done a better job than the UK of protecting investors’ money and securities. At the least, managers and the clients whose as- sets they manage are happier with the US perfomance.

When a securities firm goes bankrupt, its creditors – lenders, trading counterparties, and the like – have to get in line and fight over what’s left over. But its clients – people and companies who just warehouse their money and securities at the firm – aren’t creditors, and are supposed to get their funds back fairly quickly.

Transferring customer accounts from a defunct firm can be complex, especially when customers allowed the broker-dealer to lend their stocks out to other clients for securities-shorting purposes. (That practice is different than allowing the firm to borrow against these securities using its own credit.)

The Lehman Bros. collapse has been the biggest stress test, ever, of how this system works. And, in the six weeks since the Lehman holding company declared bankruptcy, US regulators have done a much better job of sorting through the mess and transferring clients’ assets to other brokerage firms than have their UK counterparts.

On our side of the pond, customers’ assets have been transferred to other brokerage firms in an orderly fashion. Five days after the firm’s court filing, the Securities Investment Protection Corp., which oversees this process, said: “We [are] working with all parties to achieve what will be the fastest-ever restoration of customer accounts in the history of the Securities Investor Protection Corp.” Since then, SIPC has issued regular reports updating progress, and no one has complained.

In London, meanwhile, assets are still frozen, the process to figure out who owns what seems more complicated – and the biggest customers are not pleased with the prospects for the use of their own funds and securities anytime soon.

“Hedge funds” – some of the biggest such customers – “have been quietly shifting billions of dollars of assets out of London to the US, claiming that the US legal system provides greater protection,” reports the London-based Financial Times.

And Hedge Funds Review noted that the Managed Funds Association has sent a letter to the Bank of England to inform central bankers that “prime brokerage clients are already withdrawing their assets from the UK prime brokers/UK branches of overseas prime brokers. This development is calling into question the future of the UK prime brokerage market.”

Hedge funds are the most immediately affected, because of the sheer volume of assets they hold. But other types of money managers – whose clients also fret whether their funds are safe and easily accessible at all times – doubtless are also taking note.

None of this will save US financial-services from a severe industry-wide depression. Hedge-fund assets continue to shrink considerably on both sides of the Atlantic, and sharp pull-outs from mutual funds also show that few people are in the mood to put much money in the markets now.

And managing assets is a less profitable business than successfully taking huge, risky bets with shareholders’ and lenders’ money – as financial firms did until they lost all of those unsustainable profits.

That said, if future hedge-fund and other asset managers determine that US regulators and court administrators were better stewards of their assets than were their global counterparts, it should encourage the movement of a bigger share of global assets under management to America.

Of course, people can manage assets from anywhere in the counry, so New York would still have to work to win those asset-management jobs.

To that end, the city will benefit from inevitable sharply lower office rents and residential real-estate prices, which could lure smaller firms and partnerships to the city. But New York should also refrain from hiking income and business taxes, which would drive away potential business, and must also maintain its hard-won quality of life.

Finally, Bloomberg should cut or eliminate the 4 percent “unincorporated business tax,” which falls on small firms and partnerships. Such firms are already winning asset-management business from the bigger firms.

Nicole Gelinas, a contributing editor to City Journal, blogs at nyfiscalwatch.com.